What HN did reasonably well was to train its own users to do a bit of moderation themselves; the "bad" behaviour have good chance to just get flagged or have some user complain about your comment.
I saw that behaviour few times in some other forums and for mid-sized communities it seems to work, provided you cultivate that culture in the members
Oh no, our community has been incredibly helpful in that regard. They do report things if they see them. I was really pleasantly surprised by that to be fair. And as time goes, you lean who your most valuable contributors are and you start paying closer attention to them. Which is not to say that the automations and bots I made didn't take tons of loads off all mods on the sub.
I saw that behaviour few times in some other forums and for mid-sized communities it seems to work, provided you cultivate that culture in the members